CVE-2025-48937: matrix-sdk-crypto vulnerable to sender of encrypted events being spoofed by homeserver administrator
Description
matrix-rust-sdk is an implementation of a Matrix client-server library in Rust. matrix-sdk-crypto since version 0.8.0 and up to 0.11.0 does not correctly validate the sender of an encrypted event. Accordingly, a malicious homeserver operator can modify events served to clients, making those events appear to the recipient as if they were sent by another user. This vulnerability is fixed in 0.11.1 and 0.12.0.
Classification
CVE ID: CVE-2025-48937
CVSS Base Severity: MEDIUM
CVSS Base Score: 4.9
CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N
Problem Types
CWE-290: Authentication Bypass by SpoofingAffected Products
Vendor: matrix-org
Product: matrix-rust-sdk
Exploit Prediction Scoring System (EPSS)
EPSS Score: 0.03% (probability of being exploited)
EPSS Percentile: 7.53% (scored less or equal to compared to others)
EPSS Date: 2025-06-16 (when was this score calculated)
Stakeholder-Specific Vulnerability Categorization (SSVC)
SSVC Exploitation: none
SSVC Technical Impact: partial
SSVC Automatable: false
References
https://nvd.nist.gov/vuln/detail/CVE-2025-48937https://github.com/matrix-org/matrix-rust-sdk/security/advisories/GHSA-x958-rvg6-956w
https://github.com/matrix-org/matrix-rust-sdk/commit/13c1d2048286bbabf5e7bc6b015aafee98f04d55
https://github.com/matrix-org/matrix-rust-sdk/commit/56980745b4f27f7dc72ac296e6aa003e5d92a75b
https://spec.matrix.org/v1.14/client-server-api/#mmegolmv1aes-sha2